Databases may sometimes be configured to store structured or semi-structured data within a single field. A database may, for example, store a binary file or document in a field at some position within a row of data. When structured or semi-structured data is stored in this manner, conventional database techniques for updating the data in the field may not be adequate, since the database may not be aware of the data's internal structure. Various other techniques have been used to update structured or semi-structured data stored in a database field. However, many of these techniques have aspects that are complex and unwieldy. One of the aspects involves how targets to the update expression are specified.